1. Creating venvs/docker images for dvcs loaders:
- [x] D8500: swh.loader.mercurial
- [x] swh.loader.cvs
- [x] swh.loader.svn
2. Reference loader in staging charts:
- [x] D8501: mercurial
- [x] cvs
- [x] svn
- [x] archive
- [x] cran
- [x] debian
- [x] deposit
- [x] nixguix
- [x] opam
3. Decomission loader in staging static workers:
- [x] archive
- [x] cran
- [x] cvs
- [x] debian
- [x] deposit
- [x] svn
- [x] git
- [x] bzr
- [x] highpriority
- [x] maven
- [x] mercurial
- [x] npm
- [x] nixguix
- [x] opam
- [x] pypi